How To Dress Your Baby for Sleep By Temperature

December 20, 2022
 minutes read
Written by
Mandy Treeby
Chief Baby Sleep Consultant
Medically reviewed by
Elissa Gross
Board Certified Pediatrician & Lactation Consultant

It’s something every parent wonders: how do I dress my baby for sleep? You’ve researched so many other things about raising your baby – how to breastfeed your baby, how to nap transition - but dressing your baby for sleep is one of those things we often don’t even think about until we have the baby.

This article will answer the most common questions about dressing your baby for sleep, including how to dress your baby for winter, how to dress your baby for sleep in the summer, and what are the differences between swaddles and sleeps sacks?


The Basics of Baby Sleep Safety:

Before diving in to how to dress your baby for sleep, here are the ABCs of baby sleep safety:

A – Alone: Your baby should sleep alone in their crib or bassinet on a firm mattress.

B – On Their Back: Babies should always be placed in their crib on their backs, even if they can roll back to front and front to back.

C – Clear Crib: You baby should not sleep with blankets, pillows, or stuffed animals until they are at least 12 months. The only thing that should be in your baby’s crib is your baby and maybe extra pacifiers, if your baby use them.

What Should My Baby Wear to Sleep?

The general rule of thumb from experts and pediatricians is you should dress your baby in one more layer than you’re wearing. So, if you’re wearing just a t-shirt, your baby should have a t-shirt, plus a long-sleeved onesie.

Why Temperature Matters for Babies:

Unlike adults or older children, babies’ bodies can’t regulate their own temperature. They therefore need to be dressed appropriately for the season or environment.

Types of Sleep Garments for Babies:

It’s also important to familiarize yourself with types of baby sleep clothes:

Baby Gowns: A baby gown is a complete body cover that is open at the bottom. This makes diaper changing easier for you and also makes the garment versatile: the bottom can be tied closed in colder weather or left open if it’s warmer or your baby overheats.

Footed Sleepers: A more comprehensive type of onesie, footed sleepers are onesies that also have built in socks/shoes to keep your baby’s toes warm.

Onesie: A onesie is a short or long-sleeved leotard-like garment that often snaps or has a zipper open at the bottom or side for easy diaper changes.

Swaddle: A swaddle is a cocoon made you create from a square blanket.

Note: The American Academy of Pediatrics this year (2022) advised against weighted swaddles or hats for babies.

Sleep Sack: A wearable blanket, sleeping sacks leave your baby’s arms. It’s a great option for when your baby grows out of swaddling, which happens when they can roll over, usually around 2 months.

How Swaddling Helps Babies Sleep:

Sometimes compared to a “baby burrito,” swaddling performs many functions:

  • Swaddling keeps your baby warm.
  • Swaddling mimics the womb, helping your baby feel secure.
  • Swaddling absorbs the Moro Reflex – a natural reflex in newborns that can disrupt their sleep.

When to Stop Swaddling:

You should stops swaddling your baby when they can roll over one way, either front-to-back or back-to-front, a developmental milestone that typically happens around 2 months. After that, swaddling can pose a safety hazard.

Why Can’t Babies Sleep with Blankets?

Draping your baby in a blanket seems like the most natural thing in the world – you want them to be warm and cozy – but blankets can be very dangerous for babies because blankets can be a suffocation hazard. For that reason, babies should not have a blanket until they are at least 12-months old. If you think your baby needs another layer, follow the guidance in this article.

Common Baby Fabrics:

Muslin: A soft, natural, loosely woven fabric, muslin is super warm and breathable to keep your baby cozy but well ventilated.

Jersey Knit: Warm and soft, jersey knit is also stretchy and strong, meaning it allows your little one to move with ease, but the fabric won’t tear.

Fleece: As you may know from your own wardrobe, fleece is very warm. Some wonder “Is fleece safe for babies?” and the answer is, “yes, fleece is safe for babies.” In fact, fleece is a popular material for baby blankets and outer layers, such as onesies.

Polyester: A synthetic, petroleum-basedfabric, polyester is found in a vast variety of apparel out there, including blankets and plush toys.

The Best Temperature for Baby Sleep:

Babies sleep best in rooms that are between 68 °F and 72 °F. This is actually true for all humans – studies show between 68-72 °F is the best temperature for all of us. If you’re able to regulate the temperature in your baby’s room, keep it set in that golden range for better sleep.

Other Ways to Create a Sleep-Nourishing Environment for Your Baby:

Noise Machines: White noise machines or brown noise machines mimic the womb and drown out outside noises that may disturb your baby’s sleep, such as traffic or barking dogs.

Blackout Curtains: Your baby’s circadian rhythm is largely goverened by light, and even a little bit of light can wake up your baby in the morning or prevent them from sleeping well during a nap. To help your baby sleep well, install black out curtains in their sleep space.

Calming Scents: Calming scents such as lavender or chamomile create a soothing environment where your baby feels serene and relaxed for sleep.

If you’re struggling with your baby’s sleep, get a personalized sleep plan by taking this free sleep assessment.

How to Dress Your Baby for Sleep in Winter:

In winter you may need to dress your baby in more than the “you + 1” rule, especially if you live in a drafty or colder home.

Depending on the temperature in the room where your baby sleeps, you may need the following layers:

  • Diaper and an Undershirt
  • Pajamas
  • Sleep Sack (winter weight) or swaddle (age depending)

How to Keep Your Baby from Overheating:

Since babies can’t regulate their own heat like older kids or adults, it’s important to watch for overheating.

The signs of overheating in babies include:

  • They have red cheeks
  • They’re sweating, especially along their hairline
  • Their heart rate is elevated
  • They’re fussy
  • They develop a heat rash
  • They’re hot to the touch

If you see these signs, remove one or more of your baby’s layers to cool them down.

How Do I Dress My Baby for Sleep in 70 °F?

While babies do sleep best in rooms between 68-72 °F, you also have to make sure they’re warm enough. A baby sleeping in a room that’s 70 °F or around there should wear:

  • Diaper
  • Long-sleeved pajamas
  • Swaddle or light weight sleep sack

How Do I Dress My Baby to Sleep in the AC?

To dress your baby for air conditioning, simply follow the same temperature-dependent guidance, but also be aware of where the air vent is blowing. If it blows directly on your baby, adjust it to blow away from them.

A Guide to Dressing Your Baby by Temperature:

Note: “Tog” refers to tog rating: a scale for how warm something keeps you. One (1) Tog is perfect for a room that is 68-75 °F; 2 togs is more fit for colder rooms, such as those between 61-68 °F.

80 °F: Diaper

78 °F: Onesie

75-77 °F: Onesie + Sleep Sack .5 tog/Swaddle

71-74 °F: Sleep Sack/Swaddle (.5 tog) + Long-Sleeved Pajamas

69-70 °F: Onesie + Long-Sleeved Pajamas + Sleep Sack/Swaddle (1 tog)

64-68 °F: Long-Sleeved Onesie + Long-Sleeved Pajamas Sleep +Sack/Swaddle (1 tog)

61-63 °F: Socks + Long-Sleeved Onesie + Long-Sleeved Pajamas Sleep +Sack/Swaddle (2.5 tog)

Under 60 °F: Mittens + Socks + Long-Sleeved Onesie + Long-Sleeved Pajamas Sleep +Sack/Swaddle (2.5 tog)

Note: The American Academy of Pediatrics advises against babies wearing hats indoors.


“Safe Sleep for Baby: Reducing the Risk of SIDS,” National Institutes of Health.

“Safe Infant Sleep Environment,” Eunice Kennedy Shriver National Institute of Child Health and Human Development.

“Safe Sleep Guidelines,” The American Academy of Pediatrics.

How We Wrote This Article

The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.

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What your baby wears to sleep depends on the temperature in their room. Ideally their room is set between 68-72 °F, which is scientifically proven to be the best temperature for baby sleep. If that’s the case, your baby should sleep in their diaper, long-sleeved pajamas and a sleep sack or swaddle. Remember to watch for overheating.

The best way to tell if your baby is too cold is to feel the nape of their neck. If it’s cool, they could use another layer. If it’s hot, they may be overheating. Pale skin and slow breathing are other signs your baby is too cold. If you see those signs, warm your baby up by holding them close, skin-to-skin.

Sometimes, yes, babies will wake up if they’re too cold. Remember to dress your baby in at least one more layer than you’re comfortable wearing.

Sudden Infant Death Syndrome is mysterious, and we still don’t know what causes it. There is no evidence to suggest that being cold causes SIDS.

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